1/*
2 * BK Id: %F% %I% %G% %U% %#%
3 */
4/*
5 * This file contains the routines for TLB flushing.
6 * On machines where the MMU uses a hash table to store virtual to
7 * physical translations, these routines flush entries from the the
8 * hash table also.
9 *  -- paulus
10 *
11 *  Derived from arch/ppc/mm/init.c:
12 *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
13 *
14 *  Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
15 *  and Cort Dougan (PReP) (cort@cs.nmt.edu)
16 *    Copyright (C) 1996 Paul Mackerras
17 *  Amiga/APUS changes by Jesper Skov (jskov@cygnus.co.uk).
18 *
19 *  Derived from "arch/i386/mm/init.c"
20 *    Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
21 *
22 *  This program is free software; you can redistribute it and/or
23 *  modify it under the terms of the GNU General Public License
24 *  as published by the Free Software Foundation; either version
25 *  2 of the License, or (at your option) any later version.
26 *
27 */
28
29#include <linux/config.h>
30#include <linux/kernel.h>
31#include <linux/mm.h>
32#include <linux/init.h>
33
34#include "mmu_decl.h"
35
36/*
37 * TLB flushing:
38 *
39 *  - flush_tlb_all() flushes all processes TLBs
40 *  - flush_tlb_mm(mm) flushes the specified mm context TLB's
41 *  - flush_tlb_page(vma, vmaddr) flushes one page
42 *  - flush_tlb_range(mm, start, end) flushes a range of pages
43 *
44 * since the hardware hash table functions as an extension of the
45 * tlb as far as the linux tables are concerned, flush it too.
46 *    -- Cort
47 */
48
49/*
50 * Flush all tlb/hash table entries (except perhaps for those
51 * mapping RAM starting at PAGE_OFFSET, since they never change).
52 */
53void
54local_flush_tlb_all(void)
55{
56	/* aargh!!! */
57	/*
58	 * Just flush the kernel part of the address space, that's
59	 * all that the current callers of this require.
60	 * Eventually I hope to persuade the powers that be that
61	 * we can and should dispense with flush_tlb_all().
62	 *  -- paulus.
63	 */
64	local_flush_tlb_range(&init_mm, TASK_SIZE, ~0UL);
65
66#ifdef CONFIG_SMP
67	smp_send_tlb_invalidate(0);
68#endif /* CONFIG_SMP */
69}
70
71/*
72 * Flush all the (user) entries for the address space described
73 * by mm.  We can't rely on mm->mmap describing all the entries
74 * that might be in the hash table.
75 */
76void
77local_flush_tlb_mm(struct mm_struct *mm)
78{
79	if (Hash == 0) {
80		_tlbia();
81		return;
82	}
83
84	if (mm->map_count) {
85		struct vm_area_struct *mp;
86		for (mp = mm->mmap; mp != NULL; mp = mp->vm_next)
87			local_flush_tlb_range(mm, mp->vm_start, mp->vm_end);
88	} else
89		local_flush_tlb_range(mm, 0, TASK_SIZE);
90
91#ifdef CONFIG_SMP
92	smp_send_tlb_invalidate(0);
93#endif
94}
95
96void
97local_flush_tlb_page(struct vm_area_struct *vma, unsigned long vmaddr)
98{
99	struct mm_struct *mm;
100	pmd_t *pmd;
101	pte_t *pte;
102
103	if (Hash == 0) {
104		_tlbie(vmaddr);
105		return;
106	}
107	mm = (vmaddr < TASK_SIZE)? vma->vm_mm: &init_mm;
108	pmd = pmd_offset(pgd_offset(mm, vmaddr), vmaddr);
109	if (!pmd_none(*pmd)) {
110		pte = pte_offset(pmd, vmaddr);
111		if (pte_val(*pte) & _PAGE_HASHPTE)
112			flush_hash_page(mm->context, vmaddr, pte);
113	}
114#ifdef CONFIG_SMP
115	smp_send_tlb_invalidate(0);
116#endif
117}
118
119
120/*
121 * For each address in the range, find the pte for the address
122 * and check _PAGE_HASHPTE bit; if it is set, find and destroy
123 * the corresponding HPTE.
124 */
125void
126local_flush_tlb_range(struct mm_struct *mm, unsigned long start, unsigned long end)
127{
128	pmd_t *pmd;
129	pte_t *pte;
130	unsigned long pmd_end;
131	unsigned int ctx = mm->context;
132
133	if (Hash == 0) {
134		_tlbia();
135		return;
136	}
137	start &= PAGE_MASK;
138	if (start >= end)
139		return;
140	pmd = pmd_offset(pgd_offset(mm, start), start);
141	do {
142		pmd_end = (start + PGDIR_SIZE) & PGDIR_MASK;
143		if (!pmd_none(*pmd)) {
144			if (!pmd_end || pmd_end > end)
145				pmd_end = end;
146			pte = pte_offset(pmd, start);
147			do {
148				if ((pte_val(*pte) & _PAGE_HASHPTE) != 0)
149					flush_hash_page(ctx, start, pte);
150				start += PAGE_SIZE;
151				++pte;
152			} while (start && start < pmd_end);
153		} else {
154			start = pmd_end;
155		}
156		++pmd;
157	} while (start && start < end);
158
159#ifdef CONFIG_SMP
160	smp_send_tlb_invalidate(0);
161#endif
162}
163